in set theory, the totality of elements that do not belong to a particular class. For example, if A is the class of all psychologists, then its complementary class is the class of all people who are not psychologists.
any one of a limited set of emotions that typically are manifested and recognized universally across cultures. The list of primary emotions varies across different theorists. They often include fear, anger, joy, sadness, disgust, contempt, and surprise; some theorists also include shame, shyness, and guilt. Also called basic emotion; core emotion. Compare secondary emotion.